The Research On The Effect Of Pitting And Spalling On The Torsional Mesh Stiffness Of Gear

The gear is the most widely applying part in mechanical drive, which is also pronest to fault. At present, the driving gearing is developing along miniaturized, high-speed, standardizing direction and high speed, heavy load, low noise and high reliability have been become modern gear development direction , which has brought forward higher request to gear drive characteristic property. The meshing transmission error of the gear is one of the main causes which creates noise and vibration of the gear power transmission system. The change of the gear torsional mesh stiffness intensifies the gear transmission error, specially when the gear included the flaw, in the situation its torsional mesh stiffness to reduce, therefore caused the noise and the vibration of the system is bigger. Studying the torsional mesh stiffness of the gear has a more profound significance, to understand the causes of the transmission error of the gear and the noise of the system and diagnose the gear fault.It is the important prerequisite to establish 3-D finite element model for the right finite element analysis. In this paper, using the APDL commands of ANSYS, using the bottom-up modeling way and using mapping and freedom of integration established the 3-D with/without defective accuracy model.Calculated the gear torsional mesh stiffness must analyze the contact question. This paper presents the contact question study on several issues of methods and its range of application, which is very important significance to analyze the gear contact stress. The gear must be carried out the correct loading during the period of analyzing the 3D gear contact model. It has key effects on correct solution whether boundary conditions and loading location are correct.According to the definition of torsional mesh stiffness, the 3D contact models for defect-free and defective gear transmission were set up respectively, for researching the effect of pitting and spalling on the torsional stiffness of gear. The major work is summarized as follows:1. This article review mathematical and finite element gear models for different application purposes which researchers had established in recent decades.2. In accordance with the geometric parameters of the gear transmission, Completed accurate modeling in ANSYS environment for simulating gear transmission state.3. Calculated the involute gear contact stress by the classical contact theory of Hertz's, and compared with the result by the use of Finite Element Method, which laid the foundation for calculating the gear torsional mesh stiffness 4. Through continuous circumvolving the gears, and changing their contact position, established the stiffness relations of the two contact faces, calculated the torsional mesh stiffness of the gears in different moments.5. The main research included the torsional mesh stiffness characteristic of the with-pitting and the without-pitting gear, compared the change of the punishment function and the torsional mesh stiffness of the with-pitting and the without-pitting gear.6. Establishing a 16-DOF gear nonlinear dynamic model, and analyzed the torsional mesh stiffness application in the gear failure diagnosis.The last part is a summary of this dissertation and prospect of this research...